Abstract: Computing device, computer instructions and method process input seismic data d recorded in a first domain by seismic receivers that travel in water, the input seismic data d including pressure and particle motion measurements, including up-going and down-going wave-fields. A model p is generated in a second domain by solving an inverse problem for the input seismic data d, wherein applying an L transform to the model p describes the input data d. An L? transform, which is different from the L transform, is then applied to the model p to obtain an output seismic data in the first domain, the output seismic data having a characteristic imparted by the transform L?. The characteristic is related to pressure wave-fields and/or particle motion wave-fields interpolated at positions in-between the input seismic receivers. An image of the surveyed subsurface is generated based on the output seismic dataset.

Abstract: Methods and apparatuses characterize fracture orientations in orthorhombic adjacent layer. Seismic data with azimuthal coverage enables calculating Fourier coefficients of reflectivity at an interface between the orthorhombic adjacent layers. The phases of 2nd and 4th FCs may be used to infer the fracture orientations in the orthorhombic adjacent layers. Analysis of 2nd and 4th Fourier coefficients' phases for different incidence angles may indicate that the fracture orientations in the orthorhombic adjacent layers are aligned, orthogonal, at 45°, that one of the layers is isotropic, etc.

Abstract: A seismic exploration method includes performing a true amplitude PSDM based on an initial velocity model of a subsurface formation to obtain a reflectivity model, and then a Born modeling using the reflectivity model to generate synthetic data. An image-based reflection full waveform inversion is applied to a cost function of differences between seismic data acquired over the subsurface formation and the synthetic data to update the initial velocity model. The updated velocity model enables exploring the presence of and/or assisting in the extraction of natural resources from the subsurface formation.

Abstract: Computing device, computer instructions and method for processing energy at a free-surface reflection relating to an air-water interface. The method includes receiving input seismic data recorded with seismic sensors; receiving wave-height data that describes an actual shape of a top surface of a body of water; processing up-going energy at a receiver and down-going energy following a reflection at the sea-surface, using the input seismic data and a linear operator modified to take into account the wave-height data; and generating an image of the subsurface based on the up-going energy or the down-going energy or a combination of the input seismic data and one of the up-going or down-going energy.

Abstract: A system and method are disclosed for predicting, and optionally removing surface multiples from acquired seismic data that lacks surface consistency, such as seismic data acquired using an Ocean Bottom Cable (OBC) or Ocean Bottom Node (OBN) system where the sources are located at or near the water's surface and the receivers are located at or near the ocean's floor. By processing the acquired seismic data using seismic interferometry, source side and/or receiver side operators can be generated which satisfy the surface consistency requirement of techniques such as Surface Related Multiple Elimination (SRME) so that SRME or the like can be used to predict the surface multiples.

Abstract: A method for de-blending seismic data associated with an interface located in a subsurface of the earth, includes receiving blended seismic data E generated by firing N source arrays according to a pre-determined sequence Seq; selecting N sub-datasets SDn from the blended seismic data E; interpolating each selected sub-dataset SDn to reference positions ref, where the blended seismic data E is expected to be recorded, to generate interpolated data k; de-blending, in a processor, the interpolated data k to generate de-blended data o; and generating an image of the interface of the subsurface based on the de-blended data o.

Abstract: The orientation of the symmetry axis of an underground formation including an HTI layer is determined by comparing azimuthal Fourier coefficient of inversion results in distinct source-receiver azimuth ranges with values expected from the HTI assumption. A branch-stacking technique or prior knowledge may be used to select one of the anisotropy axis orientation values.

Abstract: PP and PS seismic data are jointly inverted in a stratigraphic grid, using different time axes for PP and PS reflections. A ratio of PP and of PS waves'travel times inside a same layer cell maintained to be a function of a ratio of a P-wave propagation velocity and of an S-wave propagation velocity therein. Since PP and PS seismic amplitudes and travel times are due to elastic properties of the same structure, they can be inverted at the same time to provide better estimates of these elastic properties.

Abstract: Methods and apparatuses for processing seismic data acquired with multicomponent sensors build an accurate S-wave velocity model of a surveyed underground formation using a full waveform inversion (FWI) approach. PS synthetic data is generated using approximative acoustic equations in anisotropic media with a P-wave model, a current S-wave velocity model and a reflectivity model as inputs. The current S-wave velocity model is updated using FWI to minimize an amplitude-discrepancy-mitigating cost function that alleviates the amplitude mismatch between the PS observed data and the PS synthetic data due to the use of the approximative acoustic equations.

Abstract: Computing device, computer instructions and method for identifying seismic traces prone to cycle-skipping in a full waveform inversion method. The method includes receiving recorded seismic data recorded with seismic sensors over a subsurface of interest; selecting a model that describes the subsurface; calculating, based on the model and the recorded seismic data, estimated seismic data; and choosing a probabilistic measure that characterizes a relationship between the recorded seismic data and the estimated seismic data. The probabilistic measure includes at least one statistical function.

Abstract: Computing device, computer instructions and method for removing cross-talk noise from seismic data and generating an image of a surveyed subsurface. The method includes receiving input seismic data D generated by firing one or more seismic sources so that source energy is overlapping, and the input seismic data D is recorded with seismic sensors over the subsurface; generating a cross-talk noise model N by replacing at least one original shot gather with a reconstructed shot gather; subtracting the cross-talk noise model N from the input seismic data D to attenuate coherent cross-talk noise to obtain processed seismic data Dp; deblending the processed seismic data Dp with a deblending algorithm to attenuate a residual noise to obtain deblended seismic data Dd; and generating the image of the subsurface based on the deblended seismic data Dd.

Abstract: A non-blended dataset related to a same surveyed area as a blended dataset is used to deblend the blended dataset. The non-blended dataset may be used to calculate a model dataset emulating the blended dataset, or may be transformed in a model domain and used to derive sparseness weights, model domain masking, scaling or shaping functions used to deblend the blended dataset.

Abstract: A system and method of interpolating seismic data is provided. The system and method form a plurality of pairwise Hankel tensors from acquired seismic data, and a respective pairwise Hankel tensor for each of a plurality of originally collected frequency slices, perform tensor completion on each of said pairwise Hankel tensors to recover a plurality of interpolated frequency slices, and combine said plurality of interpolated frequency slices with said originally collected frequency slices to form a set of trace data of a geographical area of interest.

Abstract: Methods and devices use improved FWI techniques for seismic exploration of subsurface formations including salt bodies using a travel-time cost function. In calculating the travel-time cost function, time-shifts may be weighted using cross-correlation coefficients of respective time-shifted recorded data and synthetic data generated based on current velocity model. The improved methods enhance the resulting image while avoiding cycle-skipping and issues related to amplitude difference between synthetic and recorded data.

Abstract: Methods and apparatuses for seismic exploration of an underground structure obtain improved images by integrating partial match filtering in an FWI. Filtered (auxiliary) data replaces one of the observed data and the synthetic data in the FWI's objective function to avoid cycle skipping.

Abstract: A multi-sensor electromagnetic (EM) system and method for measuring gradients of EM signals. The multi-sensor EM system includes a frame; a transmitter device attached to the frame and configured to generate a primary EM field; a receiver device attached to the frame and configured to record a secondary EM field generated by the earth after being excited by the primary EM field; and a gradient sensor device attached to the frame and configured to record a gradient of the secondary EM field.

Abstract: An electromagnetic (EM) receiver system for measuring EM signals. The EM receiver system includes a survey EM transmitter for generating survey EM signals within a first frequency range; a calibration EM transmitter for generating a calibration signal; a receiver section, including a receiver housing and a receiver, that measures both the survey EM signals and the calibration signal; and a calibration device connected to the calibration EM transmitter and to the receiver, the calibration device configured to control a frequency and waveform of the calibration signal. The calibration device is further configured to calculate a response function of the receiver, based on the calibration signal.

Abstract: Device, medium and method for generating an image of a subsurface of the earth. The method includes generating an ensemble of realizations (M) based on data related to the subsurface; applying an objective function (O) to members (m) of the ensemble of realizations (m) and corresponding estimated data to estimate a mismatch; selecting a best sensitivity matrix (G) from a plurality of sensitivity matrices associated with the objective function (O) and the ensemble of realizations (M); updating realization parameters (mpr), which are used as input for a forward model (f), to calculate the corresponding estimated data, based on the best sensitivity matrix (G); and generating an image of the subsurface based on (1) the data related to the subsurface of the earth and (2) the forward model (f) with updated realization parameters (mpr).

Abstract: A method for estimating breakdown pressure values along a wellbore starts from analyzing cuttings from locations along the wellbore to determine rock properties, including rock texture information associated with the locations. The anisotropic elastic and mechanical properties at the locations are calculated based on the rock properties and using at least one rock physics model. Rock weakness index values corresponding to the locations are then calculated based on the anisotropic elastic and mechanical properties and the rock texture information. The breakdown pressure values at the locations are estimated from the rock weakness index values.

Abstract: Methods for seismic exploration of an underground formation including at least one anisotropic layer perform a joint velocity-variation-with-azimuth, VVAz, and amplitude-variation-with-azimuth, AVAz, inversion using the azimuthal angle stacks to obtain a structural representation of the underground formation. The structural representation is used to generate scenarios for exploiting resources in at least one layer of the underground formation.